Yes America did have lions.
Information on American Lion
The American Lion existed during the Pleisticone era, it eated only meat since it had no molars. It was fiercely competitive with rival predators, the most well-known competitor is the short-faced bear. It species was spread across all of North America, with reports of finding them down all the way to Nortwestern South America. They lived under cold climate conditions and use caves and fissures for shelters.
Causes of Extinction
The main reasons for the Americon Lion's extinction is the changing environment around them and the fact humans were killin them off like the Wooly Mammoth, saber-tooth tiger, and short face bear.
Solutions of Action for Protection.
They're dead. Yeah.
Internet Source #1: http://library.sandiegozoo.org/factsheets/_extinct/lion_american/lion_american.htm
Internet Source #2: